Plastic pipes are widely used to transport natural gas under pressure. The plastic pipes are often made of polyethylene or other types of plastic that occasionally develop leaks and must be repaired.
The conventional form of repairing leaks in plastic pipes transporting natural gas involves an expensive and time consuming process. First, a large excavation is required to make the leak accessible for repair. Two clamps are then placed on the plastic pipe, one on either side of the leak. The clamps are caused to compress the plastic pipe, thereby sealing the plastic pipe and isolating the leak.
Unfortunately, squeezing the plastic pipe causes weakening of the pipe walls and makes the squeezed points vulnerable to cracking, leaking, and breakage. Also, plastic pipes with a diameter of six inches or more cannot be squeezed effectively because the large diameter cannot be compressed sufficiently to seal the flow of gas passing through the plastic pipe. Also, even where the clamp appear successful, leaking gas may occur and go undetected which produces a serious safety concern to those working on the plastic pipe repair.
Conventional repair includes employing a pair of saddle taps which are fused onto the plastic pipe near the clamps and caused to tap into the pipe to communicate with the flow of natural gas. A bypass is constructed including connecting a bypass line between the saddle taps. With the flow of natural gas restored through the bypass and the leak isolated, the leak portion of plastic pipe is removed by cutting the plastic pipe. The process also includes removing burrs that were caused by cutting the plastic pipe. A replacement section of plastic pipe is fitted and connected with collars to the existing plastic pipe near the clamps. Several other time consuming step are then necessary to complete the repair, including remove the bypass, to ready the plastic pipe for natural gas transportation. Consequently, the time, cost and effort required to repair plastic pipes under pressure shows that there is a need for an alternative approach to repairing leaks in plastic pipes.
Thus, a need exists for a safer and less expensive apparatus and method of repairing plastic pipe that may be rapidly implemented, while eliminating the dangers of leaking gas or further damaging the plastic pipe. It is to such an apparatus and method for repairing plastic pipe that the present invention is directed.